the answer

Liposome is a form of chemical membrane that helps to deliver drugs or foreign substances into cells. Instead of using virus particles to carry genes into human cells, scientists have begun to use liposomes as the vehicle in gene therapy trials. Unlike virus particles, lipsomes are considered to be safer in terms of immunogenic response. Unfortunately, these artificial carriers do not have a long evolutionary history of biological selection for high efficiency in infection. That is to say, they are very inefficient as well as non-specific in getting into target cells. Although scientists are optimistic for their application in gene therapy, it is still in its very early phase of research. Also, for CF gene therapy, the level and duration of the new gene activity are additional problems that scientists are facing, because the cells that line the (air) surface of the lung have only limited life-span and are replaced by new cells which would require repeated gene therapy treatment.

On the other hand, knowing the basic problem in the CF patients, scientists have discovered new ways to restore or bypass the missing function through other means. CF researchers are hopeful about these alternative approaches.